A man launched a murderous attack on police officers after grabbing a knife from a butcher's shop, a court has heard.

One officer suffered a knife wound that cut into his bowel and required emergency surgery. Another was cut through his cheek into his mouth, and a third suffered two deep wounds to the leg, the Old Bailey was told.

Christopher Haughton, 33, of Wembley, north London, denies the attempted murder of four officers and six other charges of assault on their colleagues.

Edward Brown QC, prosecuting, said: "Some of the officers suffered very significant injuries indeed, all the result of this defendant's violence. It was perhaps only a matter of very good fortune that some of the police officers escaped with their lives.

"One was not injured at all, although had the defendant not been stopped that officer would have received a very serious knife wound to his neck, with obvious potential consequences."

In November last year officers were called to reports of Haughton causing a disturbance in Kingsbury, north London. Attempts to calm him failed and he bit an officer's fleece, tearing it with his teeth, the court heard.

Extra backup was called for after Haughton gathered masonry and other missiles and threw them at officers, the jury was told. Police followed him for 300 metres until he went into the cutting area of a halal butcher's shop in Kingsbury Road and picked up a knife with a 20-25cm (8-10in) blade.

Brown told the jury: "The defendant was angry and as you will come to appreciate directing all his anger towards the police. The next few moments witnessed a series of frenzied and quick moving attacks by this defendant on the police using the butcher's knife which caused really significant injuries which were potentially fatal.

"And to another, the defendant came within millimetres of causing what would so easily have been a fatal injury. These were deliberate and intentional acts by the defendant towards the officers who were attempting to restrain him in what had become a very dangerous situation."

Haughton pushed one officer, PC Thomas Harding, to the ground and straddled him while bringing the knife down on his shield, the court heard. One of the strikes was so hard it went through the shield and penetrated eight inches into the officer's abdomen, perforating his bowel, Brown said.

At the time of the incident Haughton was on bail following a disturbance at his girlfriend's home a month earlier when he allegedly attacked three officers, the court was told.

Brown said: "It will become plain during the evidence that the defendant was in a disturbed state of mind at the time. In the months that followed he was diagnosed as suffering from paranoid schizophrenia."